A cobpobatioef



Get. 9, 1928. 1,686,957

' c. H. M. BULL-- ROLLER BIT Filed May 20, 1927 on T M 'INVENTOR.

BY Q7/7701] Bu.

Patented Oct. 9, 1928.

UNITE CLINTON H. M. BULL, OF HOUSTON, TEXAS,

ASSIGHOB T0 ROLLER BIT COMPANY,

0F HOUSTON, TEXAS, A COEPDRATIUH OF TEXAS.

ROLLER BIT.

Application filed May 20,

This invention relates to deep well drilling apparatus, and moreparticularly to roller bits.

The invention has for its object the provision in a roller bit oi rollercutters c isposed in a new and improved manner.

It is also the object of the invention to provide new and improved meansto mount roller cutters in bit heads.

T he invention has, as a further object, provision of a shield wherebyaccumulation between roller cutters of matter drilled thereby will beprevented.

Various other objects will appear from the following description.

The accompanying drawings are illustrative of the preferred embodiment.of the invention. F 1 is a sectional elevation oi the bit, and Fig. 2 abottom plan view thereof.

Referring specifically to the drawings, the bit head is indicated at 1,and has a shank l adapted to be screwed into the usual pipe, not shown.A water course 2 discharges into a recess in the bottom of the headhaving oppositely inclined side walls 3.

The head is also provided with recesses l in the sides thereof fromwhich recesses inwardly and downwardly inclined bores 5 lead to therecess in the bottom of the head. An nular flanges 6 are -tormedon thehead adjacent said bores. Upon each of these flanges is a bushing 7having a circumferential base flange, and upon these bushings aremounted side roller cutters 8, said cutters being slightly recessed toreceive the flanges of said bushings.

Extending through one of the bores 5 is a spindle 9 which has mounted onthe inner end thereof a bushing 10 of a form like that of bushing 7, andupon bushing 10 is mounted a comparatively large frusto-conical cutter.11.

Pin 9 has an annular flange 9 on the outer end thereof, and a squaredprojection 9" projecting from said flange, said flange resting againstthe bottom of recess 4 and said projection 9* being adapted to beengaged by a tool to move spindle 9 from the head. Spindle 9 has areduced screw-threaded inner end 9 screwed. into a support 12.

Support 12 has a shank 12 fitting in bore 5, and upon the end of thisshank a nut 13 is screw-threaded, said nut having a flange restingagainst the bottom of recess 4. Support 12 may be provided with a setscrew 14, and nut 13 with a set screw 15 to respective- 1927. Serial No.192,846.

ly lock support 12 on pin 9, and nut 13 on shank 12.

Eduppcrt 12, it will be observed, has a key 72* thereon, and key 12 fitsin diametrical slots 6* and T of annular flange 6 and bushingrespectively, thereby to lock support 12 and bushing 7 against rotationwith respect to the head.

Support 12 has a curved shield 12 integral therewith and extendingpartially around cutter 11, to prevent the inward movement of matterbetween the teeth and the consequent accumulation thereoi' between thecutters.

Bushings 'Z, "Z and 10 are of a greater width than cutters 8, 8 and 11,respectively, so that the latter will not be locked on the former, butinstead will freely revolve thereon.

The advantages of placing one lar e cutter 11 between the side rollercutters 8 will at once be apparent to those skilled in the art. in thetype of bit embodying a plurality of cross roller cutters extendingdiametrically across the recess in the bottom or' the head and betweenside roller cutters, unequal rotation of said cross roller cutters,dueto the diiierence in circumference oi the circles they respectivelydefine, causes unequal cutting and consequently unequal wear. l his in-'vention provides a novel disposition of and support for a comparativelylarge cutter which will elliciently operate upon the middle portion ofthe bottom of the hole, and a shield to direct the cuttings thrown bysaid cutter.

'lae single pin 9 is made large and strong, bore 5 and annular flange 6firmly support said pin, cutters 8 and 11 are so arranged thereon thatthey provide mutual support, and the inner end of said pin is stronglysupported by support 12. The circular portion oft support 12 restsfirmly upon and is keyed to flange 6 and bushing 7, and also rests inthe inner recessed end of cutter 8. Shank 12 is locked in bore 5 by nut13.

it will be seen from the foregoing that the disposition and support ofthe cutters is such that the cutters will easily withstand the strongforces which are exerted against the cutters of roller bits when theyare in operation.

And the parts are easily and quickly assembled and separated.

The assembly thereof may be efi'ected as follows: Bushing 7 is slippedon flange 6. Cutter 8 is slipped on bushing 7. Shank 12 of support 12 isinserted in bore 5 and nut 13 screwed the eon. SetscreW 15 is screwed into lock nut 13. Key 12 meanwhile entered slots 6 and 7. The otherbushing and cutter 8 are tien slipped on flange 6, cutter 11 heldadjacentcutter 8 and pin 9 slipped through cutters 8 and 11. A tool ismade to engage squared projection 9 and reduced screw-threaded end 9screwed into support 12-. Set screw 1 is then screwed in to lock pin 9in place.

To separate the parts, the foregoing steps are reversed.

Shield 12 eliectively directs the cuttings from cutter 11 upwardly intothe path of Water discher-ging from course 2 and accurnulation of suchcut-tings between the cutters is thereby prevented.

The invention is not limited to the specific embodiment illustrated anddescribed. Various alterations may be made Without departure from thescope oi the following claims:

I claim:

1. In a rotary boring drill, a head having a recess, a long spindle insaid recess, a cutter on said spindle adjacent said head, a secondcutter fIHStOCOI1iCELl in form, and larger than the first-mentionedcutter and mounted on said spindle adj-scent the end thereof, and asecond spindle in said recess opposite and of less length then saidfirst-incritioned spindle, and a cutter on said second spindle smallerthan said trusto-c-onical cutter.

2. In a rotary boring drill, a head having a recess, side cutters insaid recess, and a center cutter between said side cutters, said centercutter being larger than either of said side cutters, end being disposedin an in c iner position.

in u, rotary boring drill, :L heed having a recess, -e cutters in saidrecess, and a center cutter beiveen said side cutters, said centercutter being larger than either of said side cutters, and beingirusto-conicul in form and disposed in un inclined position.

4:. In a rotury boring drill, a head hav ing a re ess, and a pair ofdownwardly and are l disposed bores connnuniculing with recess, theopposite wells of said recess liar uni-rider flanges adjacent the innerends or said bores, 11 pin in one of said bores, nd a support secured tothe inner end of i and e: ending into the other of and cutters on saidpin and flanges.

)tury borin, drill, a heard huri unnnlur ilung'e on one Wall 0 a pinexeuding; from the o or said r cess, cutters on said ii '11, and aremovable device to h utters on said liange and pin and J said pin.

6. In a rotary her-in; drill, a licud halving l tlangc udpicent saidGLli iO l L. M. BULL.

